cp's OEIS Frontend

A292791 The numerator of the real part of E(2n-1, i), where E(n, x) is the Euler polynomial.

%I A292791 #20 Oct 10 2017 10:37:21
%S A292791 -1,7,-11,199,-361,8017,-63311,10775663,-37120861,2572609327,
%T A292791 -54738555011,11225458402189,-170606509547761,24269619087650437,
%U A292791 -998364772178081111,1505193846304099711711,-10065529459831250937061,2427246234079407797537347,-163790353311268893725697611
%N A292791 The numerator of the real part of E(2n-1, i), where E(n, x) is the Euler polynomial.
%C A292791 The imaginary part is +-i.
%C A292791 The denominators are powers of two; A171977(n) = 2^A001511(n).
%C A292791 For E(2n, i) see A292792.
%C A292791 a(4n) == +-1 (mod 6),
%C A292791 a(4n+1) == 5 (mod 6),
%C A292791 a(4n+2) == 1 (mod 6),
%C A292791 a(4n+3) == 1 (mod 6).
%C A292791 Inspired by A291897.
%H A292791 Robert G. Wilson v, <a href="/A292791/b292791.txt">Table of n, a(n) for n = 1..276</a>
%e A292791 a(3) = -11 since E(5, i) = -11/2 + i.
%t A292791 f[n_] := Numerator[ EulerE[2n -1, I] - I^(2n -1)]; Array[f, 19]
%Y A292791 Cf. A292792.
%K A292791 sign
%O A292791 1,2
%A A292791 _Robert G. Wilson v_, Sep 23 2017